Wednesday, January 9, 2008

Jonah's Scribe Jan. 9/2008

Jonah's Scribe


Today in class we reviewed the strategies of subtracting fractions. The strategies we went over are: Double Number Lines, Common Denomenators, Money, and Clocks.


1. Using Number Lines:
the denomenator that you chose to be the one at the end of the number line should be a number that the fractions can go into easily. Once you've made your line then divide the line into the number that is at the end of it. count the lines until you get to that fraction (7/10) and number it. At the bottom of the number line you subtract the other fraction going the other way (4/10). The tick it lands on is the answer of the subtraction question. (7/10-2/5 (4/10) =3/10)

Common Denomenators
when you have fractions that are not easy to subtract with you find common denomenators between the fractions, like the fractions
3/5 - 2/7 are not really easy to subtract but if you find a common denomenator that they both go into it would be much easier. So if we change it it would be 21/35 - 10/35 , and it is much easier to subtract with now that they both have the same denomenators.


2. Using $ Money$:
when you are using the strategy of money the denomenator is always /100. you shouldn't use fractions that don't go into 100. These fractions will work for this strategy: /2, /4, /5, /10, /20, /25, and /50. When you have a fraction like 8/10 - 2/5 you can change the fractions to 80/100 - 40/100. Then when you subtract the fractions it will be easier since they have the same denomenators.
3. Using Clocks:
when you are using clocks there are certain fractions that work with it. These fractions are /2, /3, /4, /5, /6, /10, /12, /15, /20, and /3o. Subtraction questions with those denomenators are easy to use with clocks since all of those numbers go into 60. when working with this strategy the denomenator is always /60.
These are the strategies we did in class. The questions in the pictures are not the same questions we did in class. They are questions I thought would be a good example. Except for the first one. So I guess it is done....yeah.

4 comments:

david.8.16* said...

This scribe was well done, the pictures will help anyone understand what your saying, and you wrote it down step by step on how to do the three stratagies. You also had what we did today at the top. The only thing i would have to ask about if i weren't there and had to check the scribe posts, would be anything like homework! That's all =/ haha besides that its a great scribepost! =]

Nathaniel 8-16 said...

very well done. like the pictures because it helped instead of trying to explain that one picture. and yeah what david said you could put the homework

Drea said...

Your scribe was done really well. I like how you used pictures. You explained your strategy very simple and your pictures were drawn nealty to see! Good job! I also like how you showed it step by step and used more that one strategy.

kiahna 8-16 said...

good job i like how u used paint to do your pictures!